CVE-2026-74702EPSS p6.1%
CVE-2026-74702CVE-2026-74702
Description
In the Linux kernel, the following vulnerability has been resolved:
vhost-scsi: reject feature changes after endpoint
vhost_scsi_setup_vq_cmds() runs from VHOST_SCSI_SET_ENDPOINT and allocates
each command's protection scatterlist array (prot_sgl) according to the
acknowledged VIRTIO_SCSI_F_T10_PI bit. The command pools are not rebuilt
when VHOST_SET_FEATURES changes that bit later.
Although virtio feature bits must not change after feature negotiation,
vhost_scsi_set_features() currently accepts such a request after the
endpoint is active and updates acked_features. Enabling T10-PI after
endpoint setup therefore leaves prot_sgl NULL while the I/O path follows
the new feature bit.
For a 129-page protection payload, vhost_scsi_mapal() passes the missing
first chunk to sg_alloc_table_chained():
sg_alloc_table_chained(table, 129, first_chunk=NULL,
nents_first_chunk=inline_sg_cnt)
sg_pool_index() then hits:
BUG_ON(nents > SG_CHUNK_SIZE); /* 129 > 128
Scoring
| CVSS | 8.8 () |
| Vector | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H |
| EPSS | 0.17% probability of exploitation · percentile 6.1% · 2026-10-05T12:00:23Z |
| Last modified | 2026-08-25 |